GC-MS Determination of Trifluoro-Acetic Acid in Water Sample

Traces of trifluoro-acetic acid (TFA) in water sample were enriched by multistage concentration,and TFA obtained was derivatized with methanol to form methyl trifluoro-acetate (MTFA) which is suitable for head-space sample introduction in the GC-MS determination of TFA in water.The condition of head-space sample introduction was optimized.The full-scanning mode was used for qualitative analysis,and selected ion monitoring (SIM) was used for quantitative analysis with ions having m/z 59 and 69 as characteristic ions.The detection limit (3s) of the method was 1 μg·L-1.Test for recovery obtained was made by adding standard solution to blank solution,and the values of recovery obtained were in the range of 64.3%-68.1%,the values of RSD′s (n=6) were in the range of 5.62%-5.78%.